package com.main;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;

import org.apache.commons.codec.Charsets;
import org.apache.commons.codec.binary.Base64;
import org.springframework.util.DigestUtils;

import com.b2b.utils.Tools;

/**
 * 版权：上海极和信息科技有限公司
 * 功能：加密解密 
 * 作者：朱伟峰 
 * 邮箱：zhuweifeng24@gmail.com 
 * 日期：2016年6月14日
 */
public class QEncodeUtil
{
	/**
	 * Calculates the MD5 digest and returns the value as a 32 character hex
	 * string.
	 * 
	 * @param data
	 *            Data to digest
	 * @return MD5 digest as a hex string
	 */
	public static String md5Hex(final String data)
	{
		return DigestUtils.md5DigestAsHex(data.getBytes(Charsets.UTF_8));
	}

	/**
	 * Return a hexadecimal string representation of the MD5 digest of the given
	 * bytes.
	 * 
	 * @param bytes
	 *            the bytes to calculate the digest over
	 * @return a hexadecimal digest string
	 */
	public static String md5Hex(final byte[] bytes)
	{
		return DigestUtils.md5DigestAsHex(bytes);
	}
	
	/**
	 * 将byte[]转为各种进制的字符串
	 * 
	 * @param bytes
	 *            byte[]
	 * @param radix
	 *            可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
	 * @return 转换后的字符串
	 */
	public static String binary(byte[] bytes, int radix)
	{
		return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
	}

	/**
	 * base 64 encode
	 * 
	 * @param bytes
	 *            待编码的byte[]
	 * @return 编码后的base 64 code
	 */
	public static String base64Encode(byte[] bytes)
	{
		byte[] b = Base64.encodeBase64(bytes);
		return new String(b);
//		return new BASE64Encoder().encode(bytes);
	}

	/**
	 * base 64 decode
	 * 
	 * @param base64Code
	 *            待解码的base 64 code
	 * @return 解码后的byte[]
	 * @throws Exception
	 */
	public static byte[] base64Decode(String base64Code)
	{
		return Base64.decodeBase64(base64Code);
//		return Tools.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
	}

	/**
	 * 获取byte[]的md5值
	 * 
	 * @param bytes
	 *            byte[]
	 * @return md5
	 * @throws Exception
	 */
	public static byte[] md5(byte[] bytes) throws Exception
	{
		MessageDigest md = MessageDigest.getInstance("MD5");
		md.update(bytes);

		return md.digest();
	}

	/**
	 * 获取字符串md5值
	 * 
	 * @param msg
	 * @return md5
	 * @throws Exception
	 */
	public static byte[] md5(String msg) throws Exception
	{
		return Tools.isEmpty(msg) ? null : md5(msg.getBytes());
	}

	/**
	 * 结合base64实现md5加密
	 * 
	 * @param msg
	 *            待加密字符串
	 * @return 获取md5后转为base64
	 * @throws Exception
	 */
	public static String md5Encrypt(String msg) throws Exception
	{
		return Tools.isEmpty(msg) ? null : base64Encode(md5(msg));
	}

	/**
	 * AES加密
	 * 
	 * @param content
	 *            待加密的内容
	 * @param encryptKey
	 *            加密密钥
	 * @return 加密后的byte[]
	 * @throws Exception
	 */
	public static byte[] aesEncryptToBytes(String content, String encryptKey)
			throws Exception
	{
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");	// 在linux必须手动设置
		secureRandom.setSeed(encryptKey.getBytes());
		kgen.init(128, secureRandom);

		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
		return cipher.doFinal(content.getBytes("utf-8"));
	}

	/**
	 * AES加密为base 64 code
	 * 
	 * @param content
	 *            待加密的内容
	 * @param encryptKey
	 *            加密密钥
	 * @return 加密后的base 64 code
	 * @throws Exception
	 */
	public static String aesEncrypt(String content, String encryptKey)
			throws Exception
	{
		return base64Encode(aesEncryptToBytes(content, encryptKey));
	}

	/**
	 * AES解密
	 * 
	 * @param encryptBytes
	 *            待解密的byte[]
	 * @param decryptKey
	 *            解密密钥
	 * @return 解密后的String
	 * @throws Exception
	 */
	public static String aesDecryptByBytes(byte[] encryptBytes,
			String decryptKey) throws Exception
	{
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");	// 在linux必须手动设置
		secureRandom.setSeed(decryptKey.getBytes());
		kgen.init(128, secureRandom);
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
		byte[] decryptBytes = cipher.doFinal(encryptBytes);
		return new String(decryptBytes);
	}

	/**
	 * 将base 64 code AES解密
	 * 
	 * @param encryptStr
	 *            待解密的base 64 code
	 * @param decryptKey
	 *            解密密钥
	 * @return 解密后的string
	 * @throws Exception
	 */
	public static String aesDecrypt(String encryptStr, String decryptKey)
			throws Exception
	{
		return Tools.isEmpty(encryptStr) ? null : aesDecryptByBytes(
				base64Decode(encryptStr), decryptKey);
	}

	/**
	 * 编码
	 * 
	 * @param bstr
	 * @return String
	 */
	public static String encode(byte[] bstr)
	{
		return base64Encode(bstr);
	}

	/**
	 * 解码
	 * 
	 * @param str
	 * @return string
	 */
	public static byte[] decode(String str)
	{
		return base64Decode(str);
	}

}
